Thermic telephone.



P. DE LANGE z R A. BARON VAN LYNDEN.

THERMIC TELEPHONE.

APPLICATION FILED Nov. 4. 1915.

L243,.` Patented oat. 16.1917.

Lamas,

NEDERLANDSCHE THERMO- TELEPHOON MAATSCHAPPIJ, OF UTRECHT, NETHERLANDS, A CORPORATION F THE NETHERLANDS.

` Application ined Noeinb 4, i915. 'serial no.

ToaZZ whom t may concern:

Be it known that we, PIETER DE LANGE and ROBERT AERNOUT BARON VAN LYNDEN, both subjects of the Queen of the Netherlands, and residing at Utrecht, in the Netherislands, have invented certain new and useful Improvements in Thermic Telephones, of

j `which the following is a specification.

' Said holes.

phones and particularly to the ltors employed therein.k Such conductors are `fixed in a support by` passing them through holes in said vention those parts of the heating wires l `Such widening of the holes `for instance, by increases of This invention `relates to thermic teleheat conducsupport. According to our inwhich are in said holes are provided with iattened portions which firmly hold them in This makes a reliable connection between the support and the wires andthe wire is not liable to become loose as otherwise may occur when the holes of the support are widened even to a small extent. may be caused, temperature or by shrinking. A good connection between the support and the heating wire is particularly important with respect to etching, be-

" "cause, when manufacturing on a large scale,

it is possible to obtain equal sound emitting lengths only if the "wires are firmly held in their supports, project from said supports for the same distance, and consequently the lengths for which the wires are etched will not be the y same for all wires.

ing drawings in which invention is illustrated. f tional elevation and Fig.

Reference is to be had to the accompanyan yexample of our Figure l is a sec- 2 a plan view of a support holding a heating wire according to our invention, Figs. 3 and 4 are a front and lateral view of the heating wire, respectively. All the gures are drawn kto anenlarged scale.

Both branches of the arc-shaped heating `wire are passed through holes 1l of a jsupport 12 made of insulating material, such fas Vulcan fiber.

`jects for a certain The arc of the wire prodistance over the support, as clearly shown in Fig. 1. The ends 13 of the wire branches are bent at an angle and forced into a groove 111 provided on the lower surface of support 12. j

The branches of the wires are, at some distance above their bent ends 13, provided .ritieni/irc TnLnri-ioivn.

as otherwise they will` not` Patented Oct. 16, 1917. 59,629.

with flat parts 15 which may be produced in any convenient manner, as by tongs, etc. These flattened and laterally extended parts l5 act as cutting edges when the wire is passed through the round holes 1l (enlarging such holes laterally at and above the portions 15 as indicated in Fig. l), so that the wire becomes clamped or wedged inV the holes and is securely held in position.

The wire 10 is drawn into the holes of the support bymeans of an apparatus which is so constructed as to exactly determine the length of wire projecting from the support. Thefapparatus may also serve to bend the feet 13 and to force them into groove 14.

Obviously, instead of being flat as shown the parts 15 may be of other cross-sectional shape. It is only essential that they are not circular in cross section and that part of their crosssection extends beyond the round portion of the wire. The cross section of parts 15 will, in every instance, depend onk the cross sectional form and size of the holes l1.

We claim:

1. A heatv conductor for thermic telephones, provided with end portions of uniform cross section and having adjacent to `said end portions, portionsv extending laterally beyond thecross section of saidl end portions.

2. A heat conductor for thermic telephones, Vprovided with end portions, laterally-enlarged portions adjacent to said end portions, and a loop` connecting the inner ends of said enlarged portions.

3. A heat conductor for thermic telephones, provided with end portions of uniform cross` section and having, adjacent to said end portions, portions extending laterally beyond the cross section of said end portions, and a looped portion connecting the inner ends of said laterally-enlarged portions.

4. In a thermic telephone, aholder provided with through openings of uniform relatively small cross section at. one end and of enlarged cross section at lthe other end, and a wire conductor'having securing portions extending through said openings and a looped portion connecting those ends of said securing portions which are at the wide ends of said openings.

5. In a thermic telephone, a holder pro.

vided With through openings and With a transverse groove at one end of said openconductor through `said openings and having bentfends ings, pand a, Wire seated yin said groove, part portion Within said Cp'ies zof lithis :patent may De mbtainedfor openings with edges extendingy laterally beyondtlfiey remainder'of'said portionV and in vfirm engagement 4with the holder.

In testimony Whereoilwefhave signed this lo specification'. e

extending lof .the oonductorV Y being provided PIETER DE LANGE. Y,

ROBERT AERNOUT BARON m LYNDEN.

ve Acents each,-'f`byad1essing the Commissioner of Eaten-ts, Washington). G3 l, 

